cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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strlen.S (1608B)


      1/* SPDX-License-Identifier: GPL-2.0 */
      2/* strlen.S: Sparc optimized strlen code
      3 * Hand optimized from GNU libc's strlen
      4 * Copyright (C) 1991,1996 Free Software Foundation
      5 * Copyright (C) 1996,2008 David S. Miller (davem@davemloft.net)
      6 * Copyright (C) 1996, 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
      7 */
      8
      9#include <linux/linkage.h>
     10#include <asm/asm.h>
     11#include <asm/export.h>
     12
     13#define LO_MAGIC 0x01010101
     14#define HI_MAGIC 0x80808080
     15
     16	.text
     17ENTRY(strlen)
     18	mov	%o0, %o1
     19	andcc	%o0, 3, %g0
     20	BRANCH32(be, pt, 9f)
     21	 sethi	%hi(HI_MAGIC), %o4
     22	ldub	[%o0], %o5
     23	BRANCH_REG_ZERO(pn, %o5, 11f)
     24	 add	%o0, 1, %o0
     25	andcc	%o0, 3, %g0
     26	BRANCH32(be, pn, 4f)
     27	 or	%o4, %lo(HI_MAGIC), %o3
     28	ldub	[%o0], %o5
     29	BRANCH_REG_ZERO(pn, %o5, 12f)
     30	 add	%o0, 1, %o0
     31	andcc	%o0, 3, %g0
     32	BRANCH32(be, pt, 5f)
     33	 sethi	%hi(LO_MAGIC), %o4
     34	ldub	[%o0], %o5
     35	BRANCH_REG_ZERO(pn, %o5, 13f)
     36	 add	%o0, 1, %o0
     37	BRANCH32(ba, pt, 8f)
     38	 or	%o4, %lo(LO_MAGIC), %o2
     399:
     40	or	%o4, %lo(HI_MAGIC), %o3
     414:
     42	sethi	%hi(LO_MAGIC), %o4
     435:
     44	or	%o4, %lo(LO_MAGIC), %o2
     458:
     46	ld	[%o0], %o5
     472:
     48	sub	%o5, %o2, %o4
     49	andcc	%o4, %o3, %g0
     50	BRANCH32(be, pt, 8b)
     51	 add	%o0, 4, %o0
     52
     53	/* Check every byte. */
     54	srl	%o5, 24, %g7
     55	andcc	%g7, 0xff, %g0
     56	BRANCH32(be, pn, 1f)
     57	 add	%o0, -4, %o4
     58	srl	%o5, 16, %g7
     59	andcc	%g7, 0xff, %g0
     60	BRANCH32(be, pn, 1f)
     61	 add	%o4, 1, %o4
     62	srl	%o5, 8, %g7
     63	andcc	%g7, 0xff, %g0
     64	BRANCH32(be, pn, 1f)
     65	 add	%o4, 1, %o4
     66	andcc	%o5, 0xff, %g0
     67	BRANCH32_ANNUL(bne, pt, 2b)
     68	 ld	[%o0], %o5
     69	add	%o4, 1, %o4
     701:
     71	retl
     72	 sub	%o4, %o1, %o0
     7311:
     74	retl
     75	 mov	0, %o0
     7612:
     77	retl
     78	 mov	1, %o0
     7913:
     80	retl
     81	 mov	2, %o0
     82ENDPROC(strlen)
     83EXPORT_SYMBOL(strlen)